Tubeufia Penz.&Sacc., Malpighia 11(11–12): 517 (1898).

Saprobic on decorticated or decaying woody and herbaceous substrates, often associated with other fungi, in terrestrial habitats, widespread in temperate to tropical regions. Sexual state: Ascomata superficial, seated on a subiculum, spherical to clavate-obovate, oval to ellipsoid, bright to yellowish-brown when young, brown to dark brown when mature or dry, apex rounded, narrow at base, darkly pigmented, occasionally collapsing when dry. Peridium comprising pale brown cells of textura angularis, and small textura prismatica subhyaline cells at innermost layers. Hamathecium comprising numerous filiform, septate, branched, hyaline pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, saccate or cylindric-clavate, with or without an ocular chamber. Ascospores fasciculate in ascus, elongate cylindric-subfusiform or narrowly oblong, greater than 5-septate, not constricted at septa, hyaline to pale brown, smooth-walled. Asexual state: hyphomycetous, helicosporous.

Type species: Tubeufia javanica Penz. & Sacc.

Notes: Tubeufia sensu stricto (Clade F, Fig. 2) comprises species related to T. javanica having light-coloured, superficial,smooth-walled ascomata and hyaline to pale brown, elongate cylindric-subfusiform or narrowly oblong ascospores. In this paper, we describe, illustrate and designate an epitype specimen for T. javanica (MFLUCC 12–0545), and introduce T. chiangmaiensis as a new species. By designating an epitype with sequence data we aim to stabilize the genus so that related species and asexual states can be placed in this genus. The asexual morphs of Tubeufia sensu stricto are helicosporous as four species with helicomyces-like and helicoma-like conidia cluster in Clade G, i.e. Tubeufia cylindrothecia, T. intermedium, T. lilliputeus, T. roseus and T. talbotii. However, we could not examine the characters of these strains deposited in GenBank and thus do not formally synonymize them. With the introduction of one new species below, Tubeufia sensu stricto presently comprises only two species and several putatively named strains in GenBank.